1. Field of the Invention
The present invention relates to electrochemical sensors. More specifically, the present invention is directed to an electrode for an electrochemical sensor for the measurement of vapor constituent concentration.
2. Description of the Prior Art
The conventional electrochemical detection of gases and vapors customarily used in apparatus for collecting the gases and vapors in bubblers, impingers, wetted foams, etc. The gases and vapors were thereby retained or dissolved in liquids that were subsequently analyzed by electrochemical methods, e.g., potentiometric, conductometric, Redox, etc. One such prior art device was the Leeds and Northrup "Thomas Autometer" which was used for SO.sub.2 analysis. That device bubbled an atmosphere containing the SO.sub.2 through a solution of sulfuric acid (H.sub.2 SO.sub.4) and hydrogen peroxide (H.sub.2 O.sub.2). The SO.sub.2 was dissolved, i.e., absorbed, and oxidized into sulfuric acid. The additional su1furic acid formed by this process increased the conductivity of the solution. This change in conductivity was measured by a conductometer, i.e., an electrolyte conductivity instrument. Such an apparatus is inherently incapable of being miniaturized to a hand-held or wrist-mounted size which is desirable to achieve maximum portability for field use. Further, the aforesaid prior art devices used separate trapping and measuring operations which significantly decreased the speed of analysis of the gases and vapors. Accordingly, it would be desirable to provide a gas analyzer suitable for extreme miniaturization while providing a rapid and substantially continuous gas analysis.